SOLARNET Conference: The Many Scales of the Magnetic Sun

Scaling properties of Coronal Holes photospheric magnetic fields

Not scheduled

20m

Haus H, Telegrafenberg

Poster presentation 2) Small and large-scale magnetic features – from bright points to sunspots (Observations and Theory) Small and large-scale magnetic features – from bright points to sunspots (Observations and Theory)

Speaker

Mr Matteo Cantoresi (University of Rome Tor Vergata)

Description

Coronal Holes (CHs) are regions of the solar atmosphere characterized by “open” magnetic fields from which high-velocity solar fluxes can freely emerge. Photospheric magnetic fields associated with CHs are typically characterized by an imbalance in polarity. The origin of this imbalance and the spatial scales at which this imbalance appears are still debated.
In our work we used the technique of signed measure and cancellation analysis to quantitatively characterize the scale of organization of the magnetic imbalance. This technique was applied to a sample of LoS magnetograms, acquired by the Helioseismic Magnetic Imager (HMI) instrument aboard the Solar Dynamics Observator (SDO), co-spatial to CHs and quiet-sun (non-CH) regions.
From the analysis of the SDO/HMI magnetograms we measured the scale at which the imbalance appears in the magnetograms associated with the CHs. This scale is typical of solar supergranulation.
To validate this result, we created synthetic photospheric magnetograms in which we fixed the imbalance scale and verified the signed measure and cancellation analysis technique. The results of such a simulation are presented in this work.
Our analysis supports the idea that the foot points of the coronal magnetic funnels where the fast solar wind originates are associated with the supergranular network at the photospheric level.